[Study on the differentiation of human mesenchymal stem cells into vascular endothelial-like cells]

To explore the feasibility of mesenchymal stem cells (MSCs) acting as seed cells in tissue engineering, we isolated human bone marrow MSCs and differentiated them into vascular endothelial-like cells (ELCs) in vitro. Bone marrow mononuclear cells (BMSCs) were isolated by the method of percoll density centrifugation, and seeded in Dulbecco Modified Eagle Medium supplemented with 10% fetal bovine serum. MSCs were purified through multiple adherent cultures, and differentiated into ELCs induced by endothelial cell growth medium-2 (EBM-2) medium containing vascular endothelial growth factor (VEGF), human fibroblast growth factor (hFGF), insulin like growth factors 1 (IGF-1), and human epidermal growth factor (hEGF). The relative biologic characteristics of ELCs including cell morphology and phenotype were studied by inverted microscope and flow cytometry. The induced cells were identified by immunofluorescence with CD31 and Von Willebrand factor (vWF). The results showed that the morphology of MSCs was long-spindle and vortex-like growth. After induction of differentiation, the cells were round, and similar to vascular endothelial cells (ECs). Flow cytometric analysis revealed that ELCs expressed ECs specific surface markers of CD31 and vascular endothelial cadherin (VE-cadherin), but not CD133. Immunofluorescence results also confirmed that ELCs expressed CD31 and vWF. The results suggested that ELCs possed similar cell biological characteristics with ECs. In one word, human MSCs derived from bone marrow have the potential to differentiate into ECs in vitro, and show clinical feasibility acting as ideal donor cells of vascular tissue engineering.